Oil filter including an integral filter support and housing drain valve assembly

ABSTRACT

A lubricating oil filter for internal combustion engines is disclosed herein. The oil filter includes a vertical housing closed at the top by a screw cover and includes a filter support rotatably mounted on the screw cover for removably supporting an annular filter element. The filter support includes a valve element at a bottom end thereof for closing an additional outlet port at the bottom of the housing when the cover and filter support are installed on the housing and for opening the additional outlet port when the cover and filter support are removed from the housing.

The invention relates to a lubricating-oil filter for internalcombustion engines, in particular, in accordance with the features ofthe precharacterizing clause of Patent Claim 1.

An oil filter of this kind is known from EP 06 12 549 A2.

DE 41 31 353 A1 has disclosed an oil filter with a full-flow filterinsert and a partial-flow filter insert, in which the two inserts aremounted detachably on a support mounted rotatably in the screw cover ofthis filter. In this filter, the support does not interact with anadditional outlet port in such a way that the said port is closed withthe cover closed and open with the cover open. Moreover, one of the twofilter inserts, which is there composed, in particular, of foldedfilter-web material, is supported in an insufficiently firm mannerradially at the inside over its entire length.

Taking this as a starting point, the invention is concerned with theproblem of simplifying the structure of a filter derived from thegeneric type defined in the first-mentioned publication EP 06 12 549 A2,to improve its operation and, in addition, to ensure that the filterinsert is well supported radially at the inside. The provision of goodsupport of the filter insert radially at the inside is intended toimprove its life, which is determined by strength.

A fundamental solution to this problem is achieved by means of anembodiment of the lubricating-oil filter of the relevant generic type inaccordance with the characterizing features of Patent Claim 1.

The invention is based on the idea of supporting the annular filterinsert solely on the support and, at the same time, of designing thesupport extending from the screw cover to the bottom of thefilter-housing cup as a permeable tube in the region of the filterinsert between its ends, the design being such that this tube can beused as a supporting core for the internal radial support of the annularfilter insert.

Expedient configurations of the invention are the subject-matter of thesubclaims and are explained in greater detail with reference to variousexemplary embodiments.

Exemplary embodiments of the invention are illustrated in the drawing.

All the figures show an essentially schematic representation of a filterhousing in longitudinal section. The difference between the individualembodiments consists essentially only in the various ways in which thesupport is divided in the longitudinal direction.

The following divisions are shown in the individual figures.

FIG. 1: the support comprises a bottom part, extending over almost theentire length, and a snapped-on cap,

FIG. 2: the support is divided into three parts latched together,

FIG. 3: the support comprises a top part with a cap and a bottom partlatched to the said top part,

FIG. 4: the support comprises three individual parts latched together,

FIG. 5: the support is divided into two with a division somewhat abovethe centre of the filter insert,

FIG. 6: the support is made up of a top part and a bottom part, whichare latched to one another at the level of the lower end of the filterinsert, the upper end of the support surrounding an annular filterscreen.

The filter housing comprises a filter-housing cup 1 which is open at thetop and can be closed by means of a screw cover 2. In the region of thebottom, the filter-housing cup 1 is drawn in in the manner of abottleneck.

A support 3 is mounted rotatably in the screw cover 2 by way of alatch-type fastening and accommodates an annular filter insert 4. In theregion in which it is surrounded by the filter insert 4, between theends of the latter, the support 3 is designed as a radially permeablesupporting tube 5 against which the annular filter rests radially fromthe inside. At the top, at the end facing the screw cover 2, thesupporting tube 5 is closed axially in a leak-tight manner by a cap 6.In the region of the lower end of the annular filter insert 4, thesupporting tube 5 is of radially impermeable design. At its upper end,the annular filter insert 4 rests in a radially leak-tight manneragainst the cap 6 and, at its lower end, rests in a radially leak-tightmanner in the radially impermeable region of the supporting tube 5.

In the bottom region of the filter-housing cup 1, the said bottom regionbeing drawn in in the manner of a bottleneck, a radially impermeableregion 20 of the supporting tube 5, which projects beyond the lower endof the filter insert 4, is sealed relative to the filter-housing cup 1by a ring seal 7. There is a drain valve means 22 which is attached tothe supporting tube at a point on the impermeable region 20 of thesupporting tube.

The lubricating oil to be cleaned enters, via an inlet port 8, an outerspace 9 which surrounds the filter insert 4 radially. From this outerspace 9, the oil flows through the annular filter insert into thecentral space of the latter within the supporting tube 5 and leaves thefilter-housing cup 1 as cleaned oil via an outlet port 10. The outerspace 9 is thus the dirty space of the filter and the region which lieswithin the filter insert 4 and extends downwards into thebottleneck-shaped extension of the filter-housing cup 1 is the cleanspace. The clean space and the dirty space of the filter are separatedfrom one another by the ring seal 7, the radially impermeable region ofthe supporting tube 5 being part of the dividing wall between the cleanspace and the dirty space. In its permeable region, which lies withinthe filter insert 4, the supporting tube 5 is designed in such a waythat it can serve as an internal supporting core for the filter insert.

An overflow valve 11 is built into the cap 6.

Provided in the bottleneck-like bottom region of the filter-housing cup1 is an additional outlet port 12, which is closed by the free end ofthe support 3 when the screw cover 2 is closed.

When the screw cover 2, which is rotatably linked to the support 3, isopened, the additional outlet port 12 is automatically opened since theclosure piece of the support 3 slides out of the open aperture of thisadditional outlet port 12.

Removing the support 3 from the filter-housing cup 1 also opens the sealbetween the clean space and dirty space provided by the sealing ring 7,allowing cleaned and uncleaned oil to flow out through the additionaloutlet port 12 together.

In order to be able to manufacture the support in a simple manner fromplastic, for example, it is divided one or more times over its length.The individual separate sections are latched together by means of springtongues and counterbearings. The divisions and methods of latching areillustrated in the individual figures and are shown with sufficientclarity there to be comprehensible without further explanation.

In the embodiment according to FIG. 6, an annular screen filter 13 isprovided at the upper end of the supporting tube 5, between the latterand the peripheral wall of the screw cover 2. The said filter serves asa coarse filter for any lubricating oil which flows through the overflowvalve 11. The screen filter 13 is composed overall of flexible plasticwith filter areas reinforced by webs and has the shape of a ring with aU shaped cross-section. By means of its U legs, which are alignedparallel to the filter axis, the screen filter 13 is clampedleak-tightly clasp-fashion between the upper end disc 14 of the filterinsert 4 and the peripheral wall of the screw cover 2. The screen filter13 can be snapped axially in the manner of an undercut onto an annularcollar of the end disc 14 by means of its radially inner U leg. Thismakes it possible to handle and install the screen filter 13 as part ofthe filter insert 4. Within the screw cover 2, the screen filter 13 canalso be supported axially on the end of the screw cover 2 by radial ribs15.

We claim:
 1. A lubricating oil filter for internal combustion enginescomprising:a filter housing cup including an open top, a sidewall, abottom wall, an inlet adjacent said bottom wall, an outlet tubeextending from said bottom wall, said outlet tube having an interiorsurface and first and second outlet ports, wherein said first outletport is located at a lower end of said outlet tube and said secondoutlet port is positioned above said first outlet port; a screw coverfor closing the open top of said filter housing cup; a filter supportdisposed within said filter housing cup, the filter support having afirst end that is rotatably connected to said screw cover by aconnecting means and a second end including a valve member thatsealingly engages said first outlet port when said cover fully closesthe open top of said filter housing, wherein said filter supportincludes a tubular upper imperforate section adjacent said cover and atubular lower imperforate section that removably and sealingly engagesan upper portion of the interior surface of said outlet tube at alocation above said first and second outlet ports, said filter supportincluding a first radially permeable section disposed between thetubular upper and lower imperforate sections of said filter support,said filter support including a second radially permeable sectiondisposed on said tubular lower imperforate section and connected to thevalve member for permitting flow from an interior of said tubularperforated section to said second outlet port via said lower tubularimperforate section, wherein said tubular upper and lower imperforatesections and said first and second radially permeable sections and saidvalve member are integrally connected together so that said filtersupport can be removed from said housing cup as an integral unit;filtering means surrounding the first radially permeable section of saidsupport tube, means for removably sealing an upper end of the filteringmeans to said tubular upper imperforate portion of the support tube, andmeans for removably sealing a lower end of said filtering means to thetubular lower imperforate portion of said support tube; whereby saidscrew cover and said filter support including said valve member can beremoved from said filter housing cup as an integral unit, and wherebyremoval of said integral unit from said filter housing cup removes saidvalve member from said first outlet port to permit oil to drain fromsaid filter housing via said first outlet port.
 2. Oil filter accordingto claim 1, wherein the filter support (3) comprises as seen over itsaxial length, individual elements having means to be latched together.3. Lubricating-oil filter according to claim 1 comprising an overflowvalve (11) built in a cap (6) disposed at a top of the tubular upperimperforate section of the filter support (3).
 4. Lubricating-oil filteraccording to claim 3, comprising the overflow valve (11) has arrangedupstream thereof in the screw cover (2) supporting the support (3), anannular filter screen (13) with a U-shaped cross section which isclamped leak-tightly radially between a peripheral wall of the screwcover (2) and an upper end disc defining the sealing means at the upperend of said filtering means by means of U-members having legs extendingin parallel alignment to a longitudinal axis of the filtering means. 5.Lubricating-oil filter according to claim 4, comprising means forlatching the filter screen (13) in an axially fixed manner to the enddisc (14) of the filter insert (4).
 6. Lubricating-oil filter accordingto claim 5, comprising the latching means is provided at an encirclingannular shoulder on the end disc (14).
 7. Lubricating-oil filteraccording to claim 1, comprising the support (3) having a cross-shapedcross-section in the radially permeable region which is situated betweenthe radially impermeable, axially bounded region of the supporting tube(5) and the free end of that support (3), which is closing theadditional outlet port (12) at the bottom of the filter housing cup (1),when the cover (2) is closed.
 8. A lubricating oil filter for internalcombustion engines comprising:a filter housing cup including an opentop, a sidewall, a bottom wall, an inlet adjacent said bottom wall, anoutlet tube extending from said bottom; a screw cover for closing theopen top of said filter housing cup; a filter support disposed withinsaid filter housing cup, the filter support having a first end that isrotatably connected to said screw cover by a connecting means, whereinsaid filter support includes a tubular upper imperforate sectionadjacent said cover and a tubular lower imperforate section thatremovably and sealingly engages an upper portion of the interior surfaceof said outlet tube, said filter support including a first radiallypermeable section disposed between the tubular upper and lowerimperforate sections of said filter support; filtering means surroundingthe first radially permeable section of said support tube, an upper enddisk for removably sealing an upper end of the filtering means to saidtubular upper imperforate portion of the support tube, and a lower enddisk for removably sealing a lower end of said filtering means to thetubular lower imperforate portion of said support tube; an overflowvalve built in a cap disposed at a top of the tubular upper imperforatesection of the filter support; wherein the overflow valve has arrangedupstream thereof, in the screw cover supporting the support, an annularfilter screen with a U-shaped cross section which is clampedleak-tightly radially between a peripheral wall of the screw cover andsaid upper end disc by means of U-members having legs extending inparallel alignment to a longitudinal axis of the filtering means. 9.Lubricating-oil filter according to claim 8, comprising means forlatching the filter screen (13) in an axially fixed manner to the enddisc (14) of the filtering means (4).
 10. Lubricating-oil filteraccording to claim 9, comprising the latching means is provided at anencircling annular shoulder on the end disc (14).